Cryogenic treatment technology" or "ultra-cryogenic treatment technology" (referred to as "cryogenic technology") is a new process that has risen in recent years to improve the strength and wear resistance of medium and excellent metal workpieces. The so-called cryogenic technology is the use of cold media, such as Liquid nitrogen is used as a cooling medium to subject the quenched metal materials to cryogenic or ultra-zero cryogenic treatment to change the microstructure of metals, engineering plastics, ceramics and other materials, thereby improving the wear resistance of the materials and Component life.
After quenching of metal parts, the unstable austenite in the structure will be partially transformed into more stable martensite. However, because the complete transformation temperature (Mf) of many high-grade alloys can be as low as -200 ° C, general quenching technology cannot achieve Complete transformation of structure. Only during the cryogenic process, the metal parts are cooled to -200 ° C or below, can complete conversion of retained austenite to martensite be achieved. At the same time, under cryogenic conditions, metastable martensite will reduce supersaturation and precipitate and disperse ultrafine carbides with a size of only 20 ~ 60 Å. These small dispersed carbides can hinder the movement of dislocations when the material is plastically deformed, thereby greatly enhancing the wear resistance of metal parts. The change of the martensite lattice also reduces the internal micro stress of the metal parts and strengthens the matrix structure, so that the hardness, impact toughness and wear resistance of the metal parts are significantly improved.
The cryogenic technology is different from any other traditional surface treatment technology in that the structural changes caused by the cryogenic technology and the core of the workpiece are an integral treatment of parts. As a result, the part being processed can be ground repeatedly without changing its performance. This feature also extends component life several times further.
Cryogenic technology not only does not change the size of the part when processing metal parts, on the contrary, the processing process will reduce the internal stress generated by quenching, thereby enhancing dimensional stability.
Cryogenic technology is currently the most effective and efficient high-tech for improving the performance of metal workpieces. Features are consumables, low power consumption, and no environmental pollution. At present, this technology has been widely used in aerospace, marine, military, manufacturing, automotive, hardware tools, sports equipment and other industries.
